@mcnees Thanks for the reminder about “barns”! Spent several years developing an experiment to accurately measure cross-sections of small molecules in the infrared. Eventually got the limit of detection down to <0.1 barns, and used it to slowly and _very_ carefully(*) collect data that eventually helped resolve an 80-year old mystery in atmospheric physics.

@mcnees * I say _very_ carefully, but in reality you could never be too careful. One day I left my experiment idling and went home for dinner. While I was eating I got a call from the NIST fire department, who were in my lab because the water cooling loop for my high voltage laser failed catastrophically and flooded the lab. Good times. 😎